American Lexi Thompson comfortably won the inaugural Indy Women in Tech Championship, the last tournament before the final major of the season.The 22-year-old shot a four-under-par 68 to finish on 19 under, four strokes clear of New Zealand's overnight leader Lydia Ko in Indianapolis."It's a big confidence booster going into the last major of the year," said Thompson.The Evian Championship in Evian, France, starts on Thursday.Victory was Thompson's ninth on the LPGA Tour.Ko fell away with a double bogey at the par-four 11th hole at the Brickyard Crossing Golf Course in Indianapolis.Australian Minjee Lee was one shot further back in third, while England's Mel Reid and Holly Clyburn finished in a share of 30th on six under.The three-day, 52-hole event was a new tournament this year.